MathematicsEasy63×since 2002Q3694If x === 3 tan t and y === 3 sec t, then the value of d2ydx2{{{d^2}y} \over {d{x^2}}}dx2d2y at t =π4,= {\pi \over 4},=4π, is :A132{1 \over {3\sqrt 2 }}321B162{1 \over {6\sqrt 2 }}621C322{3 \over {2\sqrt 2 }}223D16{1 \over 6}61Check answerSkip